The Manual

PURPOSE OF NUCLEAR SAFETY MANUAL

The Nuclear Safety Manual establishes and outlines the requirements for safe handling, transport, and control of nuclear gauges that contain radioactive materials. This manual should be used to provide personnel that either use or are responsible for equipment containing radioactive material, with information and instructions to ensure safe and proper operation of the equipment; and to state how the licensee fulfills the requirements found in its application for a radioactive materials license.

The regulations and guidelines outlined in this manual apply to all persons who actively work with radioactive materials. This manual shall provide key NRC, Agreement State and USDOT regulations, safe operating procedures in handling, transporting, storage and utilization of gauges. Primarily we will be referencing the moisture/density gauges because it is by far the most frequently used nuclear gauge, however, the information also applies to operators of thin lift gauges. It is intended that this manual provide and ensure that all employees involved with radioactive materials are aware of the radioactive material license, the obligations of the license and basic safety practices associated with operating nuclear equipment.

When working with nuclear equipment personal and public safety is our foremost concern. Attending and successfully passing this class is one of the two requirements needed to operate the nuclear device. The second requirement is to be issued a personal monitoring device.

This manual cannot address all situations and field conditions but it gives the reader the basic concepts for nuclear safety and operation procedures. This document is considered a training tool and a reference for those employees actively engaged in overseeing and operating equipment containing radioactive materials.

Common sense, sound judgement and adherence to all regulations should always be exercised by all personnel involved in this area of work.

Regulatory Agencies

Any questions or problems that evolve concerning defects, compliance or noncompliance that cannot be resolved at the agency level by Radiation Safety Officer are referred to the NRC or Agreement State.

THIS MANUAL WILL ADDRESS THE FOLLOWING

CONCERNS

to protect the public and employees from gauge generated radiation

The Legal obligations that must be met to operate nuclear gauges

Required documentation that VDOT must retain on gauges, transport containers and operating technicians

Financial benefits of using nuclear gauges. The cost-effectiveness of using nuclear gauges to monitor density.

TABLE OF CONTENTS

SECTION I – RADIATION SAFETY & REGULATORY REQUIREMENTS

Radiation Simplified I-1 Type of Nuclear Radiation I-4 Radiation Danger I-9

Limiting Exposure I-10 Basic Concepts of Nuclear Science I-14 Tracking your Radiation Dose I-16 Dosimeter I-17 Film Badges I-19 Radiation Exposure Report I-21 Ionizing Effects of Radiation I-23 State Policy I-24 Prenatal Exposure Policy I-24 Effects of Radiation Exposure I-28

SECTION II – PORTABLE GAUGE THEORY & OPERATION

Nuclear Gauges Self Regulation Licenses Evaluation of Safety Procedures Leak Testing, Cleaning, Battery Charging Storage Requirements, Handling Procedures Transportation and Shipping, Labels, Posting of Notices and Signs Accident Instructions

Emergency Notification II-60

TABLE OF CONTENTS (cont.)

APPENDIX A

Materials Manual of Instructions Sec. 105.02 A-22

APPENDIX B

Terms and Definitions B-1 Bibliography B-10

APPENDIX C

CFR 10 Part 19 -Inspection Instructions C-1 Report of Investigations CFR 10 Part 20 -Standard for Protection C-16 3CFR 10 Part 21 -Reporting of Defects and C-70 Noncompliance Regulatory Guide 8.13 C-81

NUCLEAR SAFETY AND NUCLEAR HAZARDOUS MATERIALS

AGENDA

REGISTRATION

SECTION I – RADIATION SAFETY & REGULATORY REQUIREMENTS

Radiation Simplified Type of Nuclear Radiation Radiation Danger Limiting Exposure Basic Concepts of Nuclear Science Tracking your Radiation Dose Dosimeter Film Badges Radiation Exposure Report Ionizing Effects of Radiation State Policy Prenatal Exposure Policy Effects of Radiation Exposure

SECTION II – PORTABLE GAUGE THEORY & OPERATION

Nuclear Gauges Thin Layer Gauges Self-Regulation License Review Leak Testing Evaluation of Safety Procedures Cleaning Bottom Plates Battery Charging Storage Requirements Handling Procedures Transportation Shipping Labels Posting of Notices and Signs Shipping Accident Instructions Emergency Notification CLOSED BOOK EXAM & REVIEW  

NUCLEAR SAFETY AND NUCLEAR HAZARDOUS MATERIALS

RECERTIFICATION AGENDA

Book Review • USNRC Policy Revisions • VDOT Policy • Gauge Storage Security Transportation Maintenance • Accident Response Policy Vehicle/Construction Equipment Theft Fire • Closing Statements

SECTION ONE

RADIATION SAFETY & REGULATORY

REQUIREMENTS

RADIATION SIMPLIFIED

WHAT IS RADIATION?

Radiation in a variety of forms is familiar to all of us. Light is radiation we can see. Heat is radiation we can feel. Ultraviolet and X-ray we neither see nor feel. None of the four can be heard or smelled. All are like light because they do not continue after the source (bulb) is turned off or removed.

Radiation is as old as the universe. Stars are intensely radioactive; our earth now only slightly so. Ever since his first appearance, man has been exposed to both visible and invisible radiation from thesun. Like sunshine and rain, thunder and lightning, radioactive substances, until very recently, occurred only in nature.

Radiation from radioactive material is a stream of fast flying particles or waves, which came from tiny units of matter, called atoms. Atoms of a single element often consist of different kinds that behave alike chemically, yet have slightly different weights. These varieties are called "isotopes". The atoms of stable isotopes are not radioactive, but those of unstable or radioactive substances give off portions of themselves, and change into other isotopes in the process.

Man-made radiation in the form of X-rays was discovered in Germany in 1895. Since that time we have learned much about radiation. In France natural radioactivity was first identified with uranium. Within two years, one of its main sources was isolated--the naturally radioactive element, radium. Invisible rays from this element were soon found to be of three kinds: (1) Alpha, heavy particles which travel but an inch or so in air, (2) Beta, lighter particles which travel a few feet, and (3) Gamma, waves similar to those of light, but too short to be seen by the human eye, which penetrate to considerable distances, even through several inches of lead. In recent years a new form of radiation has been discovered, an induced radiation that is not naturally occurring. Induced radiation called neutron radiation. Neutron Radiation comes in two types, fast and thermal neutrons.

Shortly after the discovery of radium, man learned that for millions of years another form of invisible radiation had been coming at him from outside the earth's atmosphere. The source of these particles, called "cosmic rays", is still unknown. We do know, however, that they are stopped to some extent by the earth's atmosphere, and that if we were to live in Denver, Colorado, or elsewhere at a high elevation, cosmic radiation would be two to four times as intense as it is at sea level. This is why scientists investigating cosmic rays employ balloons and aircraft to collect information at high altitudes.

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Natural radioactive substances are widely distributed. They exist in minute quantities in our bodies, in the water we drink, the air we breathe, the soil we cultivate, even in the materials we use for building. Along with the cosmic radiation from outer space, these tiny sources have been sending out invisible radioactive signals for millions of years. It is against this background of natural radiation that man has lived in the past and lives today. This so-called "background radiation" varies slightly from one locality to another, and also with rain or snowfalls.

Within ten years of their discovery, practical uses were found for both X-rays and radium. X-rays proved valuable in locating bone fractures, in identifying diseases and as a supplement to radium in the treatment of cancer. You probably had a chest x-ray recently or a picture of your teeth. If so, you have been exposed to a relatively harmless amount of X-radiation administered by your own doctor or dentist.

When you have a chest X-ray taken with the common type of automatic equipment, you receive approximately 300 millirem. As far as the medical profession knows, this is harmless. During an examination of the stomach or intestines, patients frequently receive a series of exposures over a period of a few hours which may total 15 or 20 rem. To render a person sterile, the sex organs alone would have to receive a single dose of 400 -800 rem, and even more if the total amount were not given at one time.

Two naturally occurring radioactive materials, lead-210 and polonium, are commonly present in tobacco. Both of these longer-lived decay products of radon are deposited and retained on large, sticky leaves of tobacco plants. When the tobacco is made into cigarettes and the smoker lights up, the radon decay products are volatilized and enter the lungs. The resulting dose to small segments of the bronchial epithelium of the lungs of the approximately 50 million smokers in the U. S. is estimated to be about 16 rem per year. Cigarettes probably represent the single greatest source of radiation exposure to smokers in the U. S. today. The dose to the whole body from smoking two packs of cigarettes is estimated to be about 1.3 rem -more than ten times the long-term dose-rated limit for members of the public.

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30 millirem 5 millirem

30 millirem 40 millirem

40 millirem 3 millirem

Natural Radiation Man-made radiation Examples: Examples: Cosmic Rays: 30 millirem 6,000 miles jet flight: 5 millirem Soil: 30 millirem Medical X-rays: 40 millirem Body: 40 millirem Misc. products: 3 millirem

Fallout: 4 millirem

Total dose/yr 100 millirem Total dose/yr: 52 millirem

Accumulated dose/yr: 152 millirem

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Within the past years, man has learned to take naturally stable atoms and make them artificially radioactive. It is these radioactive varieties, or "radioisotopes", which are proving to be among the most useful tools in the entire history of science. Because they are radioactive, their radiation tells where they are, even if the amount is extremely small. Their location or movement within the plant or animal tissue and in industrial and chemical processes, can therefore, be traced by sensitive recording instruments. Used in this manner, radioisotopes are spoken as "tracers".

TYPES OF NUCLEAR RADIATION

Alpha Particles -Alpha particles are comparatively large, heavy particles of matter which have been ejected from the nucleus of an radioactive material with very high velocity. The velocity with which these particles leave the nucleus determines the distance (range) that they will travel in any substance. An alpha particle carries a net positive electrical charge of two and an atomic mass of 4.00277. Thus, the alpha particle is equal to the nucleus of a helium atom, which contain two protons and two neutrons. However, when we compared the speed of alpha to that of beta and gamma, we find this to be relatively slow rate as might be expected due to alpha's size and weight. Alpha rays are literally small pieces of matter traveling through space at speeds of 2,000 to 20,000 miles per second. Alpha radiation has little external penetrating power, but can be harmful if you breathe or swallow radioactive elements.

Beta Particles -Beta particles are identical to high-speed electrons. They carry a negative electrical charge of one and are extremely light, traveling at speeds nearly equal to the speed of light, 186,000 miles per second. Although the atomic nucleus does not contain free electrons, only protons and neutrons, the electrons, which are emitted as beta particles, result from the spontaneous conversion of neutron into a proton and an electron. The neutron, which lost or emitted the beta particles, has become a proton with a positive charge and thus the atom has been changed. Beta radiation is fast moving atomic particles with some penetrating power -beta radiation is frequently found inside a medical or research environment.

Gamma Rays -Gamma rays are a type of electromagnetic radiation which travel with the speed of light. They have no measurable mass or electrical charge. We have become accustomed to the use of X-rays in the medical field. X-rays and gamma rays are similar, but there are two important differences between them. While there is some overlapping, gamma rays are generally of a higher frequency. The basic difference, however, is their source. Gamma rays originate in the nucleus while X-rays originate in the cloud of electrons about the nucleus. The emission of an alpha or beta particle from the nucleus of an atom almost invariably leaves the nucleus with an excess of energy and will be accompanied by the emission of gamma rays to reach ground or stable condition. This type of radiation has greater penetrating power than medical X-rays, and is often used in portable nuclear gauges.

Neutron Radiation -Neutron Radiation consist of penetrating atomic particles that result from collisions between cosmic rays and atoms in the atmosphere, and from some specialized man-made sources. The Neutron is another type of radiation, which accompanies certain types of nuclear reactions but is not encountered in natural radioactive decay. However, certain elements when bombarded by alpha particles form a radioactive source gives off fast neutrons. For example, when

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Beryllium is bombarded by alpha particles, fast neutrons are emitted. This type of radiation is used in our portable nuclear gauges.

Cosmic Radiation -These are highly energetic atomic particles that originate from the sun and stars and penetrate the earth's atmosphere.

Alpha Particles -Alpha particles lose their energy rapidly and, hence, have a limited range, only about 2 inches to 3 inches in air, and are completely stopped by a sheet of paper. When the alpha particle is stopped, stabilized, or reaches ground state, it has picked up two electrons, which are available in space, thus making it a neutral helium atom.

Beta Particles -The Beta particle does not lose its energy as rapidly as the alpha particle. This is due to the fact that it is a very small particle, has less charge than the alpha particle, and is moving at a higher rate of speed. The range of beta particles in air is 6 feet to 25 feet. Most beta particles will penetrate paper but can be stopped by such materials as aluminum, glass and plastics.

Note: Both alpha and beta particles lose energy as they collide with other atoms, and produce ionization. This is also the case with Gamma rays, but they are less likely to interact with other atoms because a Gamma ray is a wave and not a particle.

Gamma Rays

A. Gamma rays do not consist of particles, have no mass, travel at the speed of light and do not lose their energy as either alpha or beta particles. Thus, gamma rays produce no direct ionization by collision as do alpha and beta. Gamma rays lose their energy by three processes known as the Photoelectric Effect, the Compton Effect and Pair Production.

B. Gamma rays are highly penetrating. The effect of air on a gamma ray is so small it is not practical to measure the range of gamma radiation in terms of inches, feet or but its penetrating power is measured in terms of the amount of material that will be required to reduce the gamma rays to some fraction of its original value.

C. Photoelectric Effect -As a gamma ray or photon passes through an atom, it may transfer all its energy to an orbital electron ejecting it from the atom. If the ray carries more energy than necessary to remove the electron from its orbit, this excess energy can be transferred to the electron in the form of Kinetic energy. These electrons are referred to as Photoelectron and the process is known as the Photoelectric Effect.

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Compton Effect -The Compton Effect does not completely absorb the energy of the gamma ray. A gamma ray loses a part of its energy to a free or loosely bound orbital electron but will continue as a scattered gamma ray of lower energy.

E. Pair Production -Pair Production occurs only with high-energy gamma rays. In this process, as the ray approaches the nucleus of the absorbing atom, it completely converts itself into a pair of electrons -one positive and one negative.

The Periodic Table is a standard table that lists the elements in groups arranged according to the atomic weight. There are 103 elements of which 89 were found in a natural environment. The nuclear sources element found in the gauges we use in VDOT testing are Cesium-137, Cs; Beryllium, Be; and Americium-241, Am.

PERIODIC TABLE OF ELEMENTS

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Symbols of Elements -Elements are identified by one-letter or two-letter symbols representing its chemical name. H for hydrogen; CL for chlorine; Na for sodium, etc. These symbols are referred to by the nuclear physicist as Symbol N. The Atomic Number of an element tells how many protons the nucleus contains which, of course, also equals the number of electrons in orbit. The number which indicates the atomic number is 30 in the above example. The final identifying number is the Atomic Mass Number, 65.38, which represents the sum of the protons and neutrons in the nucleus.

In certain elements, it is found that different atoms of the same element have the same number of protons but vary in the number of neutrons. Atoms of the same element which have different numbers of neutrons are known as ISOTOPES. Since the number of neutrons vary, the weight of the various atoms of the same element will not be the same. For example, there are three isotopes of hydrogen, which are hydrogen, containing zero neutrons; deuterium, containing one neutron; and tritium, containing two neutrons. Many of the isotopes are stable, but some are unstable, and, therefore radioactive. Altogether, there are over 1,200 isotopes. Most elements have two or more isotopes. While the number of neutrons in the nucleus does not materially affect chemical behavior of an element, the neutron to proton (N:P) ratio of the nucleus does affect the atom in other ways.

There is an important characteristic about the atom, which should be understood when studying radioactivity. It has been stated that the number of neutrons in the nucleus may range from zero to almost 150, depending upon the element. It has already been stated that the number of protons determines the element; that is, all atoms of the same element have the same number of protons.

The Cesium-137 is the radioactive isotope of the element Cs which produces gamma radiation. This type of radiation is employed in the moisture density gauges (3400 series) and thin layer gauges (4640 series) for determining density. The Beryllium/Americium 241 source is also found in all our moisture/density gauges and in the asphalt content gauges. The interaction of these elements produce the neutron radiation needed in determining moisture and asphalt content. The Americium 241 Beryllium is not present in the thin layer gauge (4640 series).

Source Encapsulation

To meet the requirements as "SPECIAL FORM", the radioactive material must be encapsulated to prevent contamination. The first encapsulation is provided for in that the metallic Cesium material is an integral part of a glass bead. The glass bead is then fusion welded inside a stainless steel capsule. This source capsule is fusion welded into the 3400 source rod to provide for a triple encapsulation. The Americium-241: Beryllium material is compressed into pellet form. This pressed pellet is fusion welded in two separate stainless steel capsules and is contained within the instrument in another stainless steel housing embedded in lead. The activity of these sources is a nominal 8 milliCuries of Cesium-137 and a nominal 40 milliCuries of Americium-241: Beryllium in the moisture/density gauge. In the asphalt content gauges however, the activity is greater, with a nominal 100 milliCuries Americium-241: Beryllium source.

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All nuclear gauges use a radioactive source that is placed in a special double capsule. This capsule, which can be as small as the eraser on the top of a pencil or as large as the tube inside a roll of paper towels, is then inserted into the gauge's source housing, which shields the radiation emitted from the source.

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IS RADIATION DANGEROUS TO YOU?

Danger from radiation depends upon the degree of exposure. How dangerous is fire, or exposure to the sun? How dangerous is electricity? It depends upon your exposure.

We all use electricity, but we do not take chances. We have learned to live with these agents and we can learn to live with radiation, too.

The chances of receiving an overexposure are slight. This depends upon how much you know about radiation and the common methods for protecting yourself against it, and upon whether you are a reasonable person. You can get quite a burn from a match, but you must be close to it. So with radiation, there is little danger if you know what you are doing, and if you follow the safety rules.

Radiation effects on people were noticed shortly after the discovery of X-rays. These effects resulted from extreme exposures due to ignorance. We now have special instruments to detect and measure all types of radiation. The Roentgen has been adopted as the basic unit for radiation measurement. It is simply a label for a certain amount of radiation, just as the word, meter, is the label or word used to describe a certain distance. Roentgens are commonly referred to as "r's".

With this unit of measurement, we are able to compare radiation exposure with its effects on living tissue. Years of experiments with X-rays and radium and thousands of experiments with animals have made it possible to judge how much radiation we can stand or tolerate without harm. This tolerance level is considerably higher than the amount of exposure, which the Atomic Energy Commission Employees are permitted to receive. (Now the Nuclear Regulatory Commission, Ed.) The standard operating limit is a continuing exposure of no more than 100 mr per week, not to be received in amounts greater than 50 mr per day, except for unusual cases. Extensive experience indicates that an exposure of this amount can be given every week of your life without producing any detectable change whatsoever. This daily average is 1/30 the wartime operating limit established for the atomic bomb project.

How much radiation can you stand? The important thing is that you do not take too much at one time. Small exposures with intervals in between can add up to a fairly high amount without harmful effects because cells either recover by themselves or can be replaced by other cells. Furthermore, you may safely expose a portion of your body to a much higher amount than is permissible for the entire body. Rapidly growing cells are somewhat more sensitive to radiation than normal cells. Upon this principle is based the treatment by radiation of certain types of cancer.

Radioactive materials can be harmful if within or on the body. You should therefore, avoid inhaling radioactive substances or getting them into your food or drink, just as you avoid taking in arsenic, lead, or other poisonous substances.

The amount might be harmless, but there is no need to take chances. Radioactive materials differ widely in the rate at which they lose their radioactivity. The length of time they are kept in the body also varies. Radium and plutonium remain active for thousands of years and may be retained for long periods in the body, where as elements such as radiosodium will be quickly eliminated and

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decay in a few days. Naturally, you must be careful to avoid taking even small amounts of the more poisonous materials into your mouth or lungs. This is why eating or smoking is forbidden in some radiation areas.

Between 300 and 500 rem of X or gamma radiation given to the whole body at once would probably prove fatal. This, however is a terrific amount, a few thousand times the maximum permissible daily occupational exposure or tolerance.

As one radiation expert put it, "Tolerance" is a poor word. Operating limit is better. We can tolerate a lot more radiation than the amount we have set as our operating limit."

As a general precaution, sources of radiation are confined to special "radiation areas" in which they are either roped off or are clearly indicated. All radiation areas are marked with signs bearing the purple radiation symbol on a white background. Near the source itself will be a warning sign with the purple symbol on a yellow background and a card stating the type of radiation, its strength, and the precautions to be taken.

HOW TO LIMIT EXPOSURE TO RADIATION

Nuclear gauges are tools like a power saw or a welding torch that may be hazardous unless proper safety precautions are taken. But because the potential harm from radiation is not as obvious as the dangers from a sharp blade or a flame, the safety precautions are not as obvious either. By following a few simple rules, you can be assured that working with or around nuclear gauges will pose no threat to your health and safety.

Exposure to radiation can be limited in three ways:

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If you must work near radiation, the simplest way to limit your exposure is to stay in the vicinity as short a time as possible. If there is a time limit on your job, observe it.

A second method is to maintain a safe distance between you and the source of radiation. If in doubt as to what distance is safe, consult your RSO. In general, the effect of radiation falls off sharply as you increase your distance from its source. Double the distance and your exposure is cut to one-quarter.

Shielding varies in nature and thickness, depending upon the energy and type of particles or waves. Alpha particles are stopped by a sheet of paper or the surface layer of skin on our bodies; beta particles by a quarter of an inch of wood or an eighth of an inch of metal; gamma rays by substantial amounts of lead or concrete. Neutrons must be shielded by paraffin, cadmium, or other materials of high hydrogen content.

Special shielding materials such as paraffin and cadmium can also be used effectively to slow down and stop neutron-radiation.

CONTAMINATION

Contamination is a more serious problem than exposure because it involves actual contact between you and a radioactive substance. An external source of radiation can be removed or shielded, but you cannot run away from something inside of you or on you. If by accident you get a small amount ofradioactive material on your hands, feet, or street clothes, it might possibly be deposited in your body from the end of a cigarette, through a cut, or in your food. The longer lived materials, if not easily eliminated, might then cause trouble.

Fortunately, however, some isotopes with short half lives, or ones which are easily eliminated, are valuable in the treatment of disease. Radioiodine, for example, is taken by mouth for treatment of certain thyroid conditions; radiosodium is used in measuring the circulation of the blood; and radiophosphorus in treating some types of leukemia.

MEANS OF LIMITING EXPOSURE

No matter how low the exposure rate, if means are available to limit the exposure, we should use them. In radiation safety, there are three ways to limit or reduce exposure. These are time, distance and shielding.

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TIME

1. Time

Radiation exposure is denoted in an exposure level per time. For example, if a person were to place his of her hand on the back surface of the gauge for 1-hour, the exposure to the hand would be 15 millirems. If the hand were held on the gauge for 30-minutes, the exposure would be 7.5 millirems. For 2-hours, the exposure to the hand would be 30 millirems. The longer a person stays in a radiation field, the greater the exposure. In using a 3400 series gauge, exposure is lowered by only being with the gauge for the time required to take the measurement.

DISTANCE

2. Distance Inverse Square Rule ( Exposure Rate ) ex: 100 millirem = 1 mr distance2

10 ft2

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Radiation exposure decreases drastically over distance. For example, if we had a source of radiation that at 6 feet has a level of 1 rem per hour, the same source at 12 feet would have a level of 250 mr per hour. In using a 3400 series gauge, stand only as close as necessary to see the display of readings. In transporting the gauge, keep the gauge in the cargo compartment of the vehicle, thereby increasing the distance from the source. When the gauge is not in use, store it in a safe place away from normal work traffic.

SHIELDING

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3. Shielding

The last means of decreasing radiation exposure is to place something between you and the source to stop the radiation. In a 3400 series gauge, the Americium-241: Beryllium neutron source is sufficiently low in neutron output to negate the need for any shielding. For the Cesium-137 gamma source, when the gauge is in the shielded or "safe" position, the source is completely encased by a tungsten shield. For practical use of the gauge, no other shielding methods are necessary.

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BASIC CONCEPTS OF NUCLEAR SCIENCE

Radiation -Radiation is the conveyance of energy through space. There are many kinds of radiation; some of which are long and short radio waves and infra-red (or heat) radiation. Visible light and ultra-violet rays are forms of radiation. However, nuclear radiation, the noiseless, odorless, unseen, unfelt something, is a mystery to most of us. Science fiction movies and television programs have caused many people to have various misconceptions about nuclear radiation and its effects. One purpose of this section is to erase these misconceptions. To do this, we need to know Why and as well as the What of nuclear radiation.

Understanding Nuclear Radiation -To help us understand nuclear radiation, we must have some grasp of:

WHAT is meant by "matter" and "energy"? WHAT are the kinds of nuclear radiation? WHAT is the language of nuclear physics, the terms, signs, symbols used to describe the world of the atom and radiation? WHAT is the structure of the atom? WHAT is the nature of its parts? HOW do these parts behave? HOW is the nuclear radiation measured?

Two Physical Principles -There are two physical principles that we must understand before we talk about the atom. The first is known as the Principle of the Conservation of Matter. That is, the total mass of the material always remains the same regardless of all the rearrangements of its component parts. The second is known as the Principle of Conservation of Energy. This law states that one form of energy can be converted to another form, but the total amount of energy in the universe neither increases nor decreases. It was Einstein who showed us that mass and energy are conserved; that is E equals MC

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. Where E stands for energy, M stands for mass and C is the speed of light.

The Atom -Small as it is, the atom is composed of yet smaller particles. The terms used to describe these particles are Electrons, Protons, and Neutrons.

Nucleus -The nucleus is a heavy, dense core of the atom containing practically all of the atom's weight. The nucleus is made up of little individual balls of matter that are about the same size in all atoms. Some of these little balls are called Neutrons and some are called Protons. The nucleus is surrounded at quite some distance by Electrons, which whirl around the nucleus at tremendous speeds. Both protons and neutrons are much larger and heavier than an electron. Neutrons are electrically neutral.

Protons have a positive electrical charge. For each positively charged proton in the nucleus there is a negatively charged electron in orbit around the nucleus.

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The number of protons determines the number of electrons which are in orbit. A hydrogen atom as a whole is electrically neutral. Likewise the eight protons in the nucleus of the oxygen atom are balanced by the eight electrons in orbit. The oxygen atom also contains eight neutrons in the nucleus.

Neutrons -Things to remember about neutrons:

1 Neutrons are found in the nucleus of an atom. 2 Neutrons are electrically neutral. 3 Neutrons, like protons, are much larger and heavier than electrons. 4 Depending on the element, the number of neutrons in the nucleus may range from zero to almost 150. 5 For energy deposited per unit of body mass, fast neutrons are 10 times more damaging than gamma rays per/ounce body weight.

Protons -Things to remember about protons:

1 Protons are found in the nucleus of an atom. 2 Protons have a positive electrical charge. 3 Protons, like neutrons, are much larger and heavier than electrons. 4 For each positively charged proton in the nucleus, there is a negatively charged electron in orbit around the nucleus. In a stable atom the number of protons determines the number of electrons in orbit. 5 The number of protons determines the element; that is, all atoms of the same element have the same number of protons.

Electrons -Things to remember about electrons:

1 Electrons orbit the nucleus of neutrons and protons. 2 Electrons are very small and have practically no weight. 3 Electrons have a negative electrical charge. 4 There are the same number of electrons in orbit as there are protons in the nucleus of a stable atom.

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TYPES OF MEASURING DEVICES

The types of radiation measuring devices are divided into two basic categories. One type measures total dose while the other measures dose rate. Three different devices and their use are briefly described below.

Film Badge -Use of the film badge is based on the photographic detection technique and measures the total dose for a given period of time. Time period is usually a month because the film reading starts to fade after a month. Thermoluminescent dosimeters (TLD's) utilize crystals and typically used for 3 months.

Dosimeter -the dosimeter employs the enclosed gas volume method and measures the total or accumulated dose for any desired time period. It is not as accurate as the film badge, but a reading can easily be taken at any time to determine total dosage for that period of exposure.

Survey Meter -It also employs the enclosed gas volume method but measures the dose rate in terms of dose per hour. Survey meters are used to determine safe or dangerous levels of radiation around storage rooms, accident scenes, and the like.

KEEPING TRACK OF YOUR RADIATION DOSE

By following the time, distance, and shielding principles of radiation protection you can minimize the amount of radiation you absorb. You can also monitor that radiation dose with special measuring devices.

When developing a personnel monitoring program, each individual radiation worker must be provided a personal monitoring device. These devices should be worn only during that time the worker will be on the job. A control or background badge should also be used to provide a reference or basis against which all other badges in the group will be compared. The control badge must be left in a radiation free environment. Personal monitoring devices are issued to a specific individual and must only be used by that individual alone.

Workers who use portable gauges, or those who come into regular contact with fixed gauges, can keep track of how much radiation they receive by using a personal monitoring device. Due to the small amount of radiation that workers normally receive, these devices are not usually required, but they are available. The three most commonly used types of dosimeters are direct reading dosimeters (DRDs) and film badges or thermoluminescent dosimeters (TLDs). These devices are shown in the illustrations on the next page of this chapter.

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The DRD allows you periodically to check the amount of radiation you are receiving at any given moment. A quartz fiber within the dosimeter measures the radiation by moving along a scale and provides an indication of your exposure.

A film badge contains film that is darkened by radiation. The radiation dose can be determined by reading how dark the developed film is. TLD's contain small chips of material that absorb radiation in a measurable form. You are required to wear a film badge or TLD if stated in the license or when servicing your gauge. These devices provide a permanent record of your exposure over a given period of time. Never leave any monitoring device behind when you are away from the gauge as it will continue to absorb radiation, making it impossible to tell how much radiation you have actually received.

THERMOLUMINESCENT DOSIMETERS (TLD)

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These devices measure the amount of radiation you absorb. The DRD provides an immediate indication of your exposure, whereas the film or TLD badge measures your accumulated dosage. At a minimum, film badges should be exchanged at intervals not to exceed one month and TLD's at intervals not to exceed three months.

TLD's or thermoluminescent dosimeters are a newer technology based on the use of solid crystals or phosphors such as lithium tetra-borate (Li2B4O7:Cu) or calcium sulfate (CaSO4:Tm). The dosimeter phosphors store the energy that is released during the interaction of the incoming radiation with the phosphors.

Lithium tetraborate has a radiation response characteristic which is very close to that of human tissue, and responds precisely to X-rays and gamma rays in a wide energy range, from low energy to high energy. Because the element is very thin, the skin dose can also be determined. Lithium tetraborate crystals are also used to evaluate the neutron dose equivalent.

Calcium sulfate is very sensitive, and a very small dose can be detected with this phosphor. Low energy X-rays and gamma rays can be detected separately by utilizing the energy characteristics of the phosphor, but is insensitive to neutron radiation.

The processing of the TLD is accomplished by heating the phosphors to a precise temperature, releasing the previously stored energy in the form of light; the amount of energy released is directly related to the amount of radiation received by the wearer.

A photomultiplier tube converts a very tiny amount of light into an electrical signal large enough to process. A computer then processes this information quickly and accurately and the radiation exposure is determined.

There are numerous advantages to using TLD's:

1 Because they are not prone to fading, the regulatory agencies permit TLD exchanges on a monthly or quarterly basis. 2 TLD's are very sensitive to radiation, therefore more efficient. 3 TLD's are not sensitized due to heat. 4 TLD's are not sensitive to light. 5 TLD's provide neutron monitoring at low cost.

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Things to remember when working with film personal monitoring devices:

1 Wear the personal monitoring device when working with the gauges. 2 Place the personal monitoring device in safe storage when not being used. Do not store the film badges near the gauges or in the open or near any type of radiation. Always keep the gauge and the film badge at least 10 feet apart, when not using. 3 Do not go near X-Ray equipment with your personal monitoring device. 4 Do not stand near a television, especially a color TV or a microwave with your personal monitoring device on. 5 Do not take your personal monitoring device off the project, unless you are transporting a nuclear device. 6 Place the personal monitoring device in the records safe when not in use. Always store with the Monitor Badge. 7 Never let someone else use your personal monitoring device, and never use a personal monitoring device that belongs to someone else.

FILM BADGES

The film badge is the most common personnel radiation monitor. Film badges should be worn on the outside of the clothing such as a shirt pocket or belt loop. Film badges are used mainly to detect X or gamma radiation, beta radiation, and sometimes for neutron.

Inside the jacket is a front and rear filter (cadmium, lead, or some other type of shielding material) separated by a film pack. A window of about 1/2 inch by 3/4 inch, located in one portion of the jacket, allows "shadow" radiation (radiation with low penetrating ability) such as beta, weakly penetrating gamma and slow neutrons to enter. The film pack contains several films with the sensitivity of approximately 18 to 20 roentgens of radiation. Employees working with the gauge on table level should wear the monitoring device at shirt pocket level. Employees working with the gauge on ground level should wear the gauge at waist level.

For the detection of slow and fast neutrons, an additional sensitive fine-grain film is placed inside the jacket behind the beta-gamma film packet. Slow neutrons are stopped by the cadmium filter but penetrate through the window to the film. The interaction of the slow neutrons in the gelation of the emulsion causes protons to be ejected from nitrogen nuclei. The protons activate the silver halide grains in the emulsion and leave proton tracks in the film. When the film is developed, the tracks become visible on the proton of the film under the window.

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Fast neutrons penetrate the cadmium filter and the window. They produce recoil protons when they interact with the hydrogen nuclei of the emulsion. These protons also produce tracks on the film. The difference in densities between the shielded and window portions of the film is a measure of the slow neutrons.

After the film badges have been worn for one month, the film pack is replaced with a new film pack and the exposed film developed. The radiation exposure of the film is then determined by a comparison of test films in a densitometer. Each set of film badges have a control badge included. This control film is to measure the background radiation and any accidental exposure during mailing or processing problems. During the time that the films are being worn, the control badge must be stored in a location outside the radiation field of the gauges. They should also be stored in a cool, dark environment, such as a fireproof project safe. The control and test films are important for the correct interpretation of the exposed film.

The film badges are the legal record of each worker's exposure. Film badges must be worn when testing, performing field maintenance, performing a leak test, or shop maintenance. There are several disadvantages to using film badges:

1 Ordinarily, they are not sensitive to neutron radiation, however, at an additional cost, neutron sensitive film can be added. 2 Film is inherently sensitive to any source of light, such as the sun, photo copier's, diazo printers, and fluorescent lighting. 3 Film is sensitive to heat, and can receive an accidental exposure easily by leaving a film badge in an auto for a few hours in the summer. 4 Film badges must be exchanged monthly for development, therefore, there is more administrative time required to use them. 5 Film badges are not very efficient, and fade with time. 6 Processing film badges is time consuming because they are done individually, and by hand. 7 Film badges are sensitive to moisture and should be kept as dry as possible.

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RADIATION EXPOSURE REPORTS

The following information is needed to be issued a monitoring badge: (1) First, Middle and Last Name, (2) Social Security Number, (3) Date of Birth, and (4) Permanent Mailing Address. This information is required so records can be kept and required reports can be issued for every film badge user. An example of the "Current Radiation Exposure Report" is below.

ANNUAL RADIATION EXPOSURE REPORTS

At the beginning of each recording period the personnel monitoring badges are issued to employees and then collected at the end of the period to be read for radiation exposure. The exposure report gives monthly, quarterly, annual and accumulated DOT lifetime exposures and unused permissible lifetime exposure for each employee. Each employee receives a yearly report. (See below) All monitoring badges are color coded to help radiation safety personnel tell at a glance if personnel are wearing current monitor badge or an old one.

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IONIZING EFFECTS OF RADIATION

Radioactive materials are both used and produced in different forms to accomplish specific tasks in the manufacturing and construction industries. These materials must be continually and carefully controlled to avoid any unnecessary hazards to individuals working with these materials or the general public. Carelessness or negligence by personnel working with such materials could endanger the safety and health of many people.

Companies use equipment containing radioactive materials to accomplish certain tasks, and as part of your job assignment, you may be required to work with this equipment. The use, transportation and storage of these devices are governed by regulations established by the U. S. Nuclear Regulatory Commission, Agreement States and the United States Department of Transportation. Your company may also establish rules that you must abide by.

One of the requirements established for the use of such equipment requires that all individuals must be trained in the use of the equipment and the health risk associated with radioactive materials. Each individual must successfully complete an approved training course before performing any task utilizing the equipment. Employees can expect to receive an amount of radiation exposure that is well below the permissible exposure established by the U. S. Nuclear Regulatory Commission 10 CFR 20.1101. The Occupational Dose Limits under 10 CFR 20.1201 state that the annual limit which is more limiting of the total effective dose equivalent being equal to 5 rems; or the sum of the deep-dose equivalent and the committed dose equivalent to any individual organ or tissue other than the lens of the eye being equal to 50 rems. Total Effective Dose Equivalent per year limit to an embryo fetus of a declared pregnant woman shall not exceed 0.5 rem ( 500 millirem).

In order to address questions you may have pertaining to the potential health risk of adults and unborn children, please refer to Appendix C for information from the U.S. Nuclear Regulatory Commission’s Regulatory Guide 8.13 "Instruction Concerning Prenatal Radiation Exposure”. Information regarding occupational radiation exposure may be obtained from the Nuclear Regulatory Commission’s website, www. nrc.gov/nrc/cfr.html.

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COMPANY POLICY ON LIMITING RADIOLOGICAL EXPOSURE

Compliance with The Company’s Nuclear Safety Program.

Company Personnel shall comply with all provisions of the Company’s Nuclear Safety Program and the regulations of the U.S.DOT and N.R.C. or Agreement State governing the use, transport, and storage of gauges containing radioactive materials. It is the policy of the Company that all operators and personnel involved with equipment containing radioactive materials must know and practice the ALARA philosophy. The company shall use, to the extent practicable, procedures and engineering controls to ensure that radiation exposures are kept As Low As is Reasonably Achievable (ALARA).

Proper training is the single most important factor contributing to safety in the handling and use of nuclear equipment. Therefore only personnel who have successfully completed a Nuclear Safety Training Program are permitted to operate, transport, or handle equipment containing radioactive material. Failure to exercise prudent safety precautions and care in the use and operation of nuclear equipment and radiological monitoring equipment shall be regarded as serious violations of safety rules and this policy, and subject the offending employee to the full range of disciplinary action by the company.

PRENATAL EXPOSURE POLICY

The company places no special limitation restricting women of childbearing age that could result in job discrimination. However, the company takes the position that special protection of the unborn child should be voluntary and should be based on the joint decisions made by the worker and employer who are well informed about the possible risks involved. The dose equivalent to the unborn child from occupational exposure of the expectant mother is to be limited to 0.5 rem (500 millirem) for the entire pregnancy. Employee and Employer should work together to decide the best method for accomplishing this goal once the pregnancy has been declared.

Please refer to Appendix C for the U.S. Nuclear Regulatory Commission, Regulatory Guide 8.13, Instruction Concerning Prenatal Radiation Exposure.

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MEM

ORANDUM

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RADIOLOGICAL SAFETY

RADIATION EXPOSURE UNITS

In the relatively short time since the discovery of radioactivity -less than one hundred years ago--standards for the measurement of radiation have been developed. One of the earliest units of radiation strength, the roentgen, (R), is defined as the quantity of X or gamma radiation that produces one electrostatic unit of charge in one cubic inch (in) of air; the roentgen is therefore a measure of the ionizing effect of the radiation.

A unit based on the amount of energy absorbed is the radiation absorbed dose (RAD), which is defined as 100 ergs/gm of any type of radiation. For practical purposes, 1 rad can be considered equal to 1 Rem. In order to take into consideration the effect of various types of radiation on biological tissue, a quality factor Q, must be introduced. The product of RAD x Q is called the roentgen equivalent man (REM). The table below illustrates the Q factors for various types of radiation.

dose equivalent rems = absorbed dose rads x Q

Q FACTOR FOR VARIOUS RADIATION TYPES

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RADIATION Q DOSE (REM)

1 Rad of X-ray or gamma 1 Rad 1 rem

1 Rad of beta 1 Rad 1 rem

1 Rad of neutrons or high energy protons 10 Rad 10 rem

1 Rad due to particles heavier than protons-alpha particles (with enough energy to reach the lens of the eye.)

20 Rad 20 rem

OCCUPATIONAL EXPOSURE LIMITS

In recognition of the dangers posed by overexposure to radiation, both the United States Nuclear Regulatory Commission and agreement states have adopted a maximum of 5 rems per year radiation dose. The exposure rate is based on current federal regulations, prohibiting occupational exposure to workers under the age of 18. (A person may be employed as an authorized radiation worker when 17, but is allowed only 1/10 of normal yearly dose. The yearly occupational exposure limit is5 rem/year.

PORTION YEARLY

Whole Body 5 REM Lens of the Eye 15 REM Extremities 50 REM

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EFFECTS OF RADIATION EXPOSURE

Although studies of the effects of radiation exposure on humans continue, researchers have established levels of equivalent doses producing measurable effects on health. These effects are divided into two broad classes: 1) The health effects on the exposed individual, and 2) the decreasing white blood cell counts, and long term effects such as increased evidence of cancer. The scale (below) indicates relative amounts of exposure or dose necessary to produce health effects, while the chart on page 1-28 provides a basis for comparison to other health hazards.

EXPOSURE mrem EFFECTS Minimal dose detectable by conventional personnel monitoring

Lifetime dose from natural background radiation of 100 mrem/yr

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HEALTH EFFECTS OF RADIATION EXPOSURE TO THE WHOLE BODY

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ESTIMATES OF DAYS OF LIFE HEALTH RISK EXPECTANCY LOST (AVERAGE)

Smoking 20 Cigarettes per day 2370 (6.5 years) Overweight (by 20%) 985 (2.7 years) All accidents combined 435 (1.2 years) Auto Accidents 200 Alcohol Consumption (U.S. Average) 130 Home Accidents 95 Drowning 41 Natural Background Radiation (calculated) 8 Medical Diagnostic x-rays (U.S. Average 6 Calculated) All Catastrophes (Earthquake, etc.) 3.5 1 rem occupational radiation dose (calculated) 1 (Industry average for higher dose rate job categories is 0.65 rem/yr. 1 rem/yr for 30 years (calculated) 30  

SECTION TWO

PORTABLE GAUGE THEORY &

OPERATION

MOISTURE DENSITY GAUGE

MOISTURE DENSITY GAUGE KEYPAD

The Gauge is the portable surface moisture-density gauge containing the radioactive sources, electronics rechargeable battery packs.

Reference Standard Block is used when taking standard counts

Scraper Plate/Drill Rod Guide is used to guide the drill rod.

Drill Rod Extraction Tool is used to remove drill rod from hole.

The Drill Rod is used to drill hole for direct transmission measurements.

Two Charger/Adaptors are supplied by the factory. One DC(12 volt negative groundsystem) and one for AC

Extra Battery Cases are supplied for alkaline batteries

Transport Case is the case used to transport the gauge and parts.

Operator’s Manual, Calibration Documents, Gauge Certificates and Warranty Certificates

KEYPAD LAYOUT

GAUGE ROD POSITIONS

TAKING THE STANDARD COUNT

Gauge Start-Up

Press ON

The display screen will come on and the gauge will go through a short self-test routine. The screen will alternate between displaying the current time and the date while displaying the count time, depth and remaining battery life.

The Standard Count should be taken daily to check gauge operation and allow the gauge to compensate for natural source decay. The Reference Block is used for this operation.

Place the Reference Block on a dry, flat surface of asphalt or compacted aggregate with a density of at least 100 lb/ft

3

. The location should be a minimum of 10 feet from any building or structure and at least 33 feet from any other gauge or radioactive source. Do not use truck beds, tailgates, or tabletops to perform standard counts.

Make sure that the top and bottom surfaces of the reference block and bottom of the gauge are clean from debris. Place the gauge between the grooves on the reference block with the right side tight against the metal butt plate of the block.

Press Standard for the first display, then press Yes for the second display

Press Yes to begin the count. On completion of the count the gauge will indicate “P” to the right of the percentage figures indicates that the new counts are within the 1% density and 2% moisture limits. If the percentages are not within these limits, an F, or fail will be displayed. Take a look around. Are any other gauges close by? Is the gauge seated correctly on the reference standard block? Is the gauge base and reference standard block top both clean? Is the reference standard block on a recommended surface? If all other conditions are normal, do not accept the standard count just taken. Press NO and take another standard count. If second count fails, press YES and take 3 new standard counts. Be sure to save all counts.

Write the count on the appropriate TL-Form and press YES to accept the count. When the <READY> Display re-appears the gauge is ready to take Test Measurements.

VIEWING THE LAST FOUR STANDARD COUNTS

To view the last four (4) Standard Counts, Press STANDARD, for the display:

Press NO for the display:

Press YES for the display:

To view the Moisture Standard Counts, press YES. The display will be:

The Standard Count function may be exited by pressing any key.

BASIC PARAMETER SET-UP/SETTING MEASUREMENT UNITS

Prior to taking measurements the user should determine the unit of measurement that is required for

screen displays and/or printouts. The available selections are Metric and PCF. To execute the Set

Units function, press SHIFT and SPECIAL for:

Press YES three (3) times for the display:

Press 9 for the display:

Or, the display will be:

Press either 1 or 2 for the required units. The gauge will remain in the selected mode until reset.

COUNT TIME SELECTION

The gauge provides three (3) different count times to be used for taking readings. The longest count time, four (4) minutes, will usually provide the highest accuracy. If a quick reading is required, one of the shorter periods may be selected.

Press TIME for the display:

For example, assume that a count time of 1 minute is desired. Press 2 for the display:

Count Time 1 min

The display will return to <READY>.

MODE SELECTOR The Mode function provides for the selection of Soil or Asphalt

mode. Under Asphalt mode, the sub-mode selection of % Marshall or % Voids may be

enabled. Also, while in Asphalt mode the % voidless density selection may be enabled. To

select the Mode function, press SHIFT and MODE for the display:

SOILS MODE SELECTION

From the above display, press 1 to select Soil mode. The display is:

SOIL MODE

After a short delay, the display will return to <READY>.

ASPHALT MODE SELECTION From the first display on this page, press 2 to select Asphalt mode.

The display will be:

ASPHALT MODE -% MARSHALL

% Marshall = (WD/Marshall) x 100 If % Marshall, or % compaction, is

required, press 1 from the display above.

To enable % voids, press YES.

%VOIDS = 100 X (1-WD/Voidless)

Asphalt: %MA %Voids

The display returns to <READY>.

ASPHALT MODE – 100% MA If the 100%-MA is required, press 2 from the display above.

To enable % VOIDS, press YES. % VOIDS = 100 x

(1-WD/Voidless) After a short delay, the display

returns to <READY>.

PROCTOR FUNCTION SOIL AND AGGREGATE The gauge provides a memory of

storage for up to four different proctor of marshall values. To select or change a value, press

PROCTOR/MARSHALL key for the display.

Press 2 for:

Press 1 for:

Select a value (1-4):

Press 2 for:

Press ENTER for:

If YES then:

Choose value (1-4). Press ENTER. The screen reverts to the <READY> display. If not the screen reverts to the <READY> display.

SITE PREPARATION

Soil and Aggregate Testing -using Direct Transmission method

Safety glasses must be worn for this operation!

Surface preparations are critical to gauge performance and test result accuracy. The following procedure will help insure accurate test results. With the gauge in soil mode and proctor data stored, place the scraper plate on the surface and slide the plate back and forth to form a smooth area. Lift the plate from the surface and fill any voids or depressions and replace the plate. Press down on the plate to further level the site. Place the drill rod extraction tool over one of the rod guides on the plate before inserting the drill rod. Insert the drill rod into the rod guide and hammer the rod approximately 2 inches further than the deepest test. Remove the drill rod by pulling straight on the drill rod extraction tool. Do not remove the drill rod by moving it from side to side. Remove the scraper plate by lifting straight up to insure no debris falls into the hole.

Place the gauge on the smoothed surface and insure the source rod is over the just-drilled hole. Lower the source rod to the correct depth in the hole and release the trigger. Gently slide the gauge to the right to allow the source rod to make contact with the side of the hole. NOTE – All tests should be performed using the one-minute mode.

Base Asphalt and Aggregate Testing – using the Backscatter Method

Locate a representative area for the test site. Do not choose an area that is too fine or too coarse for testing.

Place the gauge on the test surface and insure that gauge base is resting flush. If the gauge rocks back and forth select another test site. The gauge should not rock.

ASPHALT MODE

Enable the Asphalt mode prior to taking a measurement. Refer to MODE SELECTION for more

details on gauge setup. Place the source rod in Backscatter position, making sure it locks into proper

position. Press Start. Select the desired Marshall value by pressing 1, 2, 3, or 4 for the display:

Marshall and Proctor functions are identical as far as operation is concerned. Therefore, only Marshall will be illustrated. To change a Marshall value, press 1 for:

RECALL A STORED PROCTOR/MARSHALL VALUE

To enable a previously stored value press 1. The display is:

THIN LAYER DENSITY GAUGE

THIN LAYER DENSITY GAUGE KEYPAD

The GAUGE contains electronic modules, rechargeable battery packs, detectors and the radioactive source.

The AIR GAP SPACER is used whenever a standard count is taken. The MAGNESIUM REFERENCE BLOCK p for gauge adjustment.

CHARGER/ADAPTOR provides a means to recharge gauge batteries.

TRANSPORT CASE is a USDOT approved shipping container that may be used to ship

gauge and accessories.

PRINTER connects to gauge for printing data.

KEYPAD LAYOUT

TAKING THE STANDARD COUNT

The gauge comes with a magnesium (Mg) reference block and an air gap spacer for taking the standard count. Place the reference block on a dry, flat surface at lease ten feet from any large vertical surface (i.e., concrete block wall) and at least thirty feet from any other radioactive source. The surface should be asphalt or concrete at least four inches thick.

Place the spacer on the Magnesium reference block and then place the gauge on top of the spacer. The gauge must be in the “safe” position. The handle end of the gauge should rest over the two posts on the spacer.

The standard Count is used in all density calculations to allow for the decay of the Cesium 137 source. The source will decay approximately 2% per year. It is recommended the Standard Count be taken once when you receive your new gauge and then every 6 months and recorded in a logbook. It is recommended to maintain a log of these tests for future reference.

Thin Layer Gauge

Reference Block Press

<STD> for the display:

Press <YES>.

Check the gauge position. Press <ENTER> to start the count.

After the count is completed accept the new count by pressing <YES>. The pass/fail tolerance is based on 1% variation for System 1 reference standard counts and a ½% variation for System 2 standard counts (multi-standard and single-standard mode). The last four “standard counts” stored in gauge memory may be viewed.

Press <SHIFT> and <SPECIAL>. Press either <YES> four times then <ENTER> or press <12> for the display:

To view the counts for System #2, press <YES>. TAKING A READING Prior to taking

a test select the layer thickness making sure the readings are not influenced by underlying

material.

Input the thickness of the overlay and press <ENTER>.

MARSHALL/VOIDLESS DENSITY PARAMETERS

display:

Press <YES> and input any target Marshall and voidless density values.

Press <START>:

After the count time has elapsed, the display will be:

NOTE: If Surface Voids Mode has been enabled, the surface voids density value will be

displayed. VIEWING THE COUNTS To view the actual counts for detector systems 1

and 2, press <SHIFT> and <RECALL>.

SELF REGULATIONS & THE LICENSE

The Nuclear Regulatory Commission or Agreement State is the agency responsible for ensuring the safety of people who work with radioactive by-product materials and the security of such materials. To control the risks associated with the use of nuclear by-product materials, the Agency sets strict health and safety standards for nuclear equipment, defines allowable limits for radiation exposure and frequently conducts inspections of nuclear products and facilities. The Agency enforces the regulations governing the use of radioactive by-product materials. The codes are law and they are binding upon licensees to up hold.

In addition to the regulations, licensees are governed by the provisions outlined in the license authorizing the possession of by-product material. The possession of a license obligates the licensee to scrupulously perform the actions it stated it would perform to comply with the requirements of it license. This commitment is the condition under which the licensee is able to receive and then retain the license. Failure to comply could mean a severe fine, loss of license, or both, together with the adverse publicity. The provisions of the license are just as compelling as the regulations governing nuclear safety.

Possession of a license requires the licensee to adhere to safe practices and act as self-regulator in the enforcement of regulations. The licensee is compelled to report its own infractions of rules to the regulatory agency. To enforce safety regulations periodic checks of the program should be made to see that employees are following the licensee’s radiation safety program. Instructions and radiation safety rules are an essential part of safe operations of nuclear gauges. The licensee should establish a system of records covering the receipt and transfer of nuclear gauges. You must maintain records of radiation exposure of persons working in the program and surveys are conducted to evaluate the effectiveness of radiation safety programs. A copy of the license which governs and sets binding conditions under which the licensee operates its nuclear gauges is to be kept on file. The location of the original license must be posted for pertinent viewing

LEAK TESTING

We are aware of our environment through our senses. We can see, smell, taste, hear and feel conditions that exist around us. However, none of these senses will make us aware of the presence of radiation. For this reason we must employ alternative measures to determine the presence of radiation. Survey meters or Geiger counters are tools that assist in detecting radiation, but the leak-wipe test procedure provides an additional means of evaluating leakage which leads to radioactive contamination.

The leak-wipe test is one of the safety precautions executed by the company and mandated by the regulatory agency to detect environmental radiation contamination and radiation exposure to personnel. The regulations concerning the safe use of radioactive material dictates that a sealed source be tested to ensure that the source material remain sealed so that the equipment and area around the source are not contaminated. The leak test must be made at intervals not to exceed six months and this frequency is dictated by the licensing document. All sealed sources must have a current and valid leak test record before transfer to another licensee or disposal through approved means.

The test should be capable of detecting the presence of 0.005 microcuries of radioactive material on the test sample. Records of leak test results should be kept in units of microcuries and maintained for inspection by the agency. If the test reveals the presence of 0.005 microcuries or more of removable contamination, the licensee shall immediately withdraw the sealed source from use and shall cause it to be decontaminated and repaired or to be disposed of in accordance with agency regulations. A report shall be filed within 5 days of the test with the agency.

The procedure for performing the leak test is as follows: The swab is used to wipe the areas around the sources. First, remove the key pad/control panel, look in and locate the yellow radioactive materials label, wipe the label with the swab. Reattach the keyboard. Next, tilt the gauge on its side, find the opening where the source rod protrudes out of its shielded position, wipe the opening with the same swab. Mail the swab and form.

On the Thin Layer Density Gauge locate the area directly to the left of the location where the handle mechanism enters the gauge. Use the swab to wipe the area.

Equipment needed to complete a Leak-Wipe Test: Geiger Counter and leak testing tools.

Leak Testing Tools: Swab and a scrubbing tool.

TAKING SAMPLE FOR POSSIBLE RADIOACTIVE LEAKAGE

Use a swab or specimen filter paper.

To sample the Americium sources, the keypad is removed and the swab disc is placed on a yellow radioactive label covering AM-241 source.

To sample for leakage of the cesium source, a swab or specimen disk and applied to the base opening from which the source rod is extruded. (The source rod should be in the safe position).

The area around the top of the gauge housing where the source rod enters the gauge may also be wiped to collect a sample for cesium leakage

The swab or disc is mailed in the labeled envelope.

LEAK TESTING RECORDS

The "Leak/Wipe Testing Report" is completed and placed on file by the inspector at the time the sample is taken. All gauge should be tested at the same time.

Sample identification data is posted on the form below and submitted to the Division of Consolidated Laboratory Service for evaluation. Results of this testing are reviewed, filed and maintained for review by the regulatory agency.

Inventory (Six Month Interval)

A condition of the license which authorizes the possession and use of radioactive sources, the licensee must conduct a physical inventory every 6 months of all radioactive by-product materials. The RSO should perform an inspection and review of procedures at each location, where gauges are stored. This inspection is in addition to the physical inventory done during leak/wipe testing. The individual report is then filed for review. The monitor also completes a summary of inventory, which shows the location and number of gauges stored at all locations. Any discrepancies that are found must be resolved through further investigation and correction of data.

Each component of this tracking system is critical in verifying the location and accounting for the sources as required by the agency regulations. This exercise is an important part of licensee’s Nuclear Safety Program, because it compels the interaction of all employees actively engaged in the use and management of nuclear gauges. The RSO and employees must all work together to make the program sound and accurate. A good and cooperative working relationship must be established and maintained between all segments of the nuclear program.

SAMPLE EVALUATION OF SAFETY PROCEDURES

Part I -TLD Badge Requirements 1 Are TLD badge(s) stored at least 10 ft. from nuclear gauge when gauge is in storage? 2 Are TLD badge(s) stored in the insulated, fireproof safe located in the office? 3 Have all personnel handling and/or operating nuclear gauge attended and successfully completed a radiation safety school? 4 Have all personnel handling and/or operating nuclear gauge been issued individual TLD badges and properly delegated to work with gauge? 5 Are all personnel handling or operating the gauges over the age of 18? 6 Are the TLD badges a) Kept at work location except when transporting nuclear gauge? b) Worn properly when handling or operating the nuclear gauge? c) Kept in a dry place, away from direct sunlight and excessive heat? d) Protected from damage? 7 Are gauges operated and transported in a manner that would prevent the general public from being exposed to radiation?

Part II – Transportation Requirements 1 When the nuclear gauge is transported in a vehicle, is the gauge secured in its transport case with the radioactive source in the locked position, in accordance with DOT Regulation, CFR Title 49, Part 173.412(f)? 2 When the nuclear gauge is transported on the highway, is it transported in an enclosed part of the vehicle and secured against unauthorized removal from the vehicle, in accordance with DOT Regulation, CFR Title 49, Part 173.403(c)? 3 Are the shipping containers used for transporting the nuclear gauge properly labeled, in accordance with DOT Regulation, CFR Title 49, Part 172.403(c)? 4 When the nuclear gauge is transported, are the shipping papers (bill of Lading), provided by the Central Laboratory located in the transporting vehicle within reach of the operator, and either attached to the inside of the driver’s door or placed on the driver’s seat, in accordance with DOT Regulation, CFR Title 49, Part 177.817(e)? 5 Has the individual shipper inspected the shipping container before shipment to ensure package is physically sound and that each closure device (hinges, clasp, latches, etc.) is properly installed, secured, and free of defects in accordance with DOT Regulation, CFR Title 49, Part 173.475?

Part III – Storage Requirements 1 Is the storage space for a nuclear gauge posted with “Radioactive Materials” signs, in accordance with NRC Regulation, CRF Title 10, Part 20, Section 20.203? 2 Is Form NRC-3 “Notice to Employees,” posted where the nuclear gauges are assigned, in accordance with NRC Regulation, CFT Title 10, Part 19, Section 19.11(c)? 3 Is the radioactive source, when not in use and when left unattended, stored and secured (locked, bolted, etc.) at all times against unauthorized removal from the storage place, in accordance with NRC Regulation, CFR Title 10, Part 20, Section 20.1801? 4 Is the nuclear gauge stored in an outside storage facility at least 10 ft. from the area where personnel perform their normal work duties, except when shielding is provided? 5 Are the required records of transfer maintained when the nuclear gauge is moved from one assigned area to another, in accordance with NRC Regulation, CFR Title 10, Part 30m Section 30.51 and Part 31, Section 31.5?

Signature of Responding Inspector Radiation Safety Officer

Title Date of Report

Gauge Model Serial No. Source GBg

CS# Project No. Am241/Be# District Date of Inspection

Gauge Maintenance

Moisture density gauges will provide many years of dependable service if proper maintenance is performed on a periodic basis. An important component (of these gauges) that requires maintenance is the bottom plate and sliding block located in the bottom plate of the gauge. Typical problems reported as a result of insufficient maintenance include: difficulty in raising and lowering the source rod, improper sliding block operation, and erratic moisture or density counts. Following the procedure outlined below will ensure that your gauge is maintained in the best condition.

Never attempt to remove the source rod. When the Cs-137 source is in the safe position it is surrounded by protective shielding, reducing the radiation to a safe level to performmaintenance. 1 Place the source rod in the "Safe" position. Lay the gauge on one side. Make sure you stand to the side to avoid unnecessary radiation exposure. 2 Clean the four screw heads holding the bottom plate to the gauge base. Cleaning the screw heads helps prevent stripping. Remove the four screws. 3 Remove the bottom plate and inspect for dirt build up in the cavity. If dirt is present replace the scraper ring in the bottom plate. To replace the scraper ring, remove the retaining ring with a screwdriver and remove the scraper ring. Replace with a new scraper ring. Reinstall the retaining ring. 4 Inspect the back of the bottom plate for excessive wear from the sliding block. If the plate shows excessive wear, replace with a new bottom plate. 5 Remove the sliding block. The source will be exposed at this time. Stand to one side to minimize exposure. Clean the block and the cavity with a rag and stiff brush. 6 Replace the sliding block after cleaning. Orient the block with the angled side up, toward the source. If the block is installed incorrectly the source rod will not operate.

7. Install the four screws in the bottom plate. Do Not Over-tighten the screws, as this could strip the threads.

DAILY AND WEEKLY MAINTENANCE

The Cavity formed by the scraper ring should be cleaned frequently. If the gauge is used in wet sand or concrete, the cavity should be cleaned every day. If you regularly use the gauge in soils clean the cavity when raising and lowering the source rod.

Stand Gauge on the end and stand behind the gauge to work. Remove screws from the bottom plate.

Remove the bottom plate and the lead block that shields the source rod.

Clean the area around the lead block. Clean and polish the face of the block to remove any rough surfaces. Spray with graphite. Do not get hands near the source rod.

Replace the lead block and the plate. Clean the gauge daily.

BATTERY CHARGING FOR MODEL 3440

The 3440 gauge constantly updates the battery condition. Depending on user preference, the hours remaining or the battery voltage will be displayed. A fully charged battery will last approximately 8 weeks under normal working conditions (8 hour day) before recharging is necessary.

A low battery condition is indicated by the following display:

When this display appears, there are a few hours remaining before the battery must be recharged. If necessary, for emergency use, a 30-minute recharge with the DC or AC charger provides several hours of use. After a short recharge time the Batt life display may not always indicate an accurate update of the battery life-only a full sixteen hour recharge will "reset" the Batt life indicator. Recharge batteries only when the gauge indicates it.

CAUTION!

DO NOT MIX ALKALINE AND RECHARGEABLE BATTERIES IN THE GAUGE. CHARGING MAY CAUSE ALKALINE BATTERIES TO EXPLODE!

STORAGE REQUIREMENTS

1. The storage unit for nuclear gauges on the project shall be posted with "Radioactive Material" signs. 2. The "Notice to Employees" shall be posted viewable by all employess.

3. The radioactive source, when not in use and when left unattended, shall be stored and secured (locked, bolted, etc.) at all times against unauthorized access or unauthorized removal from the storage place. 4. Gauges should be stored at least 15 feet from any permanent workstation (desk).

5. The nuclear gauge and TLD's (Film Badge) stored shall be at least 30 feet apart.

6. The required records of transfer shall be completed when the nuclear gauge is moved from one assigned area to another or when transferred to another license.

HANDLING PROCEDURES

This instrument was designed with operator safety as a prime consideration: however, as with any piece of potentially hazardous equipment, some general precautions should be observed.

1 Do not operate or attempt to operate the instrument unless you have been authorized to do so. 2 Keep the source position in the "SAFE" or stored position when not in use. 3 If required by your license or organizational procedures, wear a Film Badge or other dose measurement device when using or transporting the instrument. 4 While exposure dose levels are well within limits for radiation workers, never expose yourself to the bare source without sufficient reason for justification of the additional dose. 5 Keep all unauthorized persons out of the operating area. A suggested distance is 15 feet. The general public must not be unnecessarily exposed to radiation. 6 Maintain security of the instrument at all times. The source lock should be in place when not in use and the instrument should be kept in a locked vehicle when transported. When stored, the area should be locked. Not only is it an expensive piece of equipment but, if stolen, could be abandoned under conditions which could be a hazard to the general public. 7 Every user organization has standard operating procedures; the operator should follow those procedures and report any that he feels are unsafe. 8 Insure that the gauge has had leak test measurements at the proper intervals as required by your Radioactive Materials License. 9 If you have any doubts about use of the instrument, ASK. Your Radiation Safety Officer either has the answer or can obtain one.

GENERAL REQUIREMENT FOR THE OPERATORS / OPERATIONS OF NUCLEAR GAUGES

1. No individual shall work with or operate a device containing radioactive materials, until the individual has completed a nuclear safety training program.

2. No individual shall work with or operate a device containing radioactive materials, until the individual has been issued a monitoring device to monitor radiation exposure. The monitoring device shall be issued to and worn by only the individual to whom the badge is registered and assigned.

3. (a) No minors are allowed to be exposed to more than 10 percent of the allowable radiation exposure of an adult, or to more than a maximum of 100millirem of radiation exposure per year.

(b) Requirement 3(a) above also applies to females who are in a state of pregnancy, in that there is a potential danger of radiation exposure to the embryo or fetus.

4. No individual working with radioactive materials shall use the nuclear device in such a manner as to expose the general public to radiation at any time. (Allowable exposure to certified employees is 5000millirem per year. Anyone receiving more than 10 percent of this amount must be furnished monitoring equipment.)

TRANSPORTATION

Shipping papers must be maintained in the vehicle, within the immediate reach of the driver restrained by the lap belt. Ordinarily, a glove compartment does not meet this requirement. (49 CFR 170 – 178) provides detailed information on accessibility of shipping papers within the vehicles).

Licensees who transport radioactive packages in their vehicles must provide for adequate blocking, bracing, and tie-down of the packages to prevent shifting or movement during normal transport. Licenses also are required to provide security measures adequate to prevent the unauthorized removal of materials from the place of storage during transport. This may involve locking the packages within an external, permanently attached compartment of the vehicle, or within the cargo compartment, itself. In either case, it is necessary to remove the keys from the vehicle.

Each package must be labeled with two RADIOACTIVE YELLOW-II . Labels must be affixed on opposite broadsides of the package.

Vehicles must not be placarded when the shipment includes YELLOW-II packages.

RADIOACTIVE MATERIAL SHIPPING LABELS

The Department of Transportation regulations for hazardous materials, which became effective December 31, 1968, specify a new labeling system for radioactive materials. Hazard classification under the new system is based on the radiotoxicity of the isotope instead of the type of radiation emanating from the package.

Each radionuclide is assigned to an appropriate "transport group". And the term "transport index" is used for the dose rate from the external surface of the package.

D.O.T. specification labels, size 4" x 4", are now available with pressure-sensitive adhesive backing.

Radioactive White Radioactive Yellow

One of the above labels should be on any package containing radioactive materials during transportation. The label gives the kind of material, of radiation three feet from any surface of the container. The table below gives the limits for each label. A radiation expert should evaluate any accident involving radioactive material.

LABEL SURFACE OF 3 FEET FROM PACKAGE SURFACE OF PACKAGE

RADIOACTIVE-YELLOW II 10 MR/HR 0.5 MR/HR

SECURITY OF RADIOACTIVE SOURCES AND POSTING OF NOTICES AND SIGNS

Regulations state that each source of radiation shall be provided with a lock or outer-locked container designed to prevent unauthorized or accidental production of radiation, or removal or exposure of a sealed source. It shall be kept locked at all times, except when under the direct surveillance of authorized personnel. Each storage container likewise shall be provided with a lock and kept locked when containing sealed sources, except when the container is under the direct surveillance of authorized personnel.

Regulations state that locked radioactive exposure devices and storage containers shall be physically secured to prevent tampering or removal by unauthorized personnel.

When the gauges are stored in the field office complex, the gauges shall be locked and secured in the storage area at all times to prevent unauthorized removal.

Signs shall also be placed on the gauge in clear view warning all persons of the possible danger involved. Signs are furnished with the gauges for this purpose.

The carrying case must carry the Type A Sealed Source sign and Type II Radioactive Symbol sign at all times.

The RSO shall be notified immediately, in case of a broken or lost lock on the gauge, transport box, carrying case or trailer security chains.

Radioactive Materials signs must be posted and visible on door side opening of the storage unit. If a separate building is used, signs must be posted on all entrances.

Copies of the following notices and documents must be posted in a prominent place in every establishment where activities covered by the regulations are conducted to permit employees working in or frequenting any portion of a restricted area to observe a copy on their way to or from their place of employment.

1 Copies of the license shall also be posted for inspection at each job site. 2 The licensee’s Safety Program must be posted at each location. 3 "Notice to Employees" signs must be posted on the bulletin board. 4 Emergency Notification information which provides the phone numbers of the persons to be contacted in the event of an emergency.

RECIPROCITY

Reciprocity is the act of one regulatory agency honoring the license of another regulatory agency. Ordinarily, licensees are not allowed to use portable nuclear gauging devices outside of their licensed territories without permission of the state agency or USNRC region in which they intend to work.

Requirements to obtain reciprocity may include:

1 Three day written notification of intent to transport and use gauge(s). 2 Copy of your Radioactive Materials License. 3 Copy of the latest leak test for all gauges concerned. 4 Temporary address of use/storage area.

Reciprocity is normally granted for periods up to 180 calendar days. Some states limit the use to 30 days. If this limit is exceeded, a Radioactive Materials License for that particular state or USNRC region is required.

RADIOACTIVE CAUTIONS SIGNS

State and federal regulations require that Radiation Areas and sources of radiation be properly posted. These are the radiation warning signs and the radiological hazards they represent:

CAUTION-RADIATION AREA signs identify areas with radiation levels such that an individual could receive a dose to the whole body in excess of 5 millirems in one hour or a dose in excess of 100 millirems in any five consecutive days.

A magenta and yellow "FEDERAL OFFENSE" sign can be posted where nuclear gauge are stored. The intent of this sign is to discourage the theft of the gauge.

CAUTION -RADIOACTIVE MATERIAL signs identify containers of radioactive materials or areas where radioactive materials are stored or used.

SHIPPING

All shipments of radioactive materials, whether from industry or government, must be packaged and transported according to strict federal regulations. These regulations protect the public, transportation workers, and the environment from potential exposure to radiation. They cover a broad range of activities, including package design and testing packaging, labeling, marking, documentation (shipping papers), and routing of shipments.

Radioactive material is shipped in general commerce by highway, rail, water, and air. In over 40 years of shipping, there have been no deaths or serious injuries directly related to the radioactive nature of this cargo. This safety record is the result of effective Federal regulations that govern the use and transportation of radioactive material. The single most important factor contributing to safety in radioactive material transportation is the package used to contain the material during shipping. The higher the radioactivity of the material, the more stringent are the package requirements. Safe packages assure that even in a severe accident, harmful quantities of radioactive material will not be released.

Before a package may be used, the package design must be able to pass tests, through an independent authority, that are specified in the Federal regulations. Each package design is then certified to show that it meets Federal requirements.

The most important way to reduce the risk associated with transporting radioactive material is to use the appropriate packaging standards specified by the U. S. DOT, and NRC or Agreement State regulations, when required.

Different shipping packages are required for various types, forms, quantities, and levels of radioactivity. The type of package used for gauges is the Type A Package.

The Type A package is the required shipping container for moisture density gauges. Type A packages must demonstrate that they are able to withstand a series of tests that simulate normal transport conditions without loss of contents or shielding and no substantial reduction in the effectiveness of the package (See diagram on next page). These packages generally contain lower concentrations or smaller quantities of radioactive material such as nuclear gauges.

Note: These drawings represent basic depiction and descriptions of the test procedures that are specified in the regulations. Detailed descriptions of additional test requirements are found in 49 CFR 173.465 for Type A packages.

Markings / Labeling

Federal regulations require that shippers follow specific requirements in marking and labeling all packages containing radioactive materials. Markings provide the proper shipping name, identification and the shipper's name and address. Labels must not only identify the contents and radioactivity level but also provide an index to handling instructions. Gauge shippers use Radioactive II Labels. The appropriate label is determined by the type of material shipped and by its radiation levels.

The correct use of marking and labels is a joint responsibility of the carrier and the shipper. Markings and labels alert transportation workers to the hazardous nature of the shipment and alert emergency response personnel to follow special procedures if an accident occurs.

Reportable Quantity Designation -This applies to any package containing at least .37 GBq (10 mCi) of Am-241:Be or containing 37 G Bq (1 Ci) of Cs-137. The requirements are as follows:

1.

Water spray test for 1 hour 2. Free-fall drop test onto a flat, hard

(to simulate rainfall of 2 inches per surface (a

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drop

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3. Compression test

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5

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pound bar vertically the

1 The letters "RQ" must be stamped on the package, in association with the proper shipping name. "RQ" must be stamped on the transport case or an affixed label. 2 The letters "RQ" must be printed on the shipping paper (Bill of Lading, Shipper’s Declaration), either preceding or following the shipping name.

Shipping Papers

Properly completed shipping papers, such as bills of lading must accompany shipments of radioactive material. These papers contain detailed information on the material being transported and reference the appropriate emergency response procedures to follow if there is an accident. In addition, these documents must certify that the material is properly classified, packaged, marked, and labeled according to DOT regulations.

Drivers must keep the papers in the vehicle and make them available at all times for inspection by responsible officials.

Required Transport Documentation Checklist -Bill of lading

(visible to individuals entering vehicle) -Nuclear Accident Check List -

Source Certificate (accessible to driver) -Emergency Procedures (accessible

to driver)

When gauge is not being transported, keep shipping papers with gauge.

TYPE A PACKAGE CERTIFICATION

Troxler Electronic Laboratories, Inc. certifies that their 3000 and 4000 models contain Type A quantities of special form radioactive materials and are packed for shipment in Specification 7A Type A containers.

These containers meet the requirements of United States Department of Transportation 49CFR 173.24 and are designed and constructed to meet the standards as specified in 49 CFR 173.403 and 49 CFR 173.465. These containers are marked and labeled in conformance with 49 CFR 173.444. These regulations are in agreement with the Regulations for the Safe Transport of Radioactive Materials (Safety Series No. 6) of the International Atomic Energy as Amended.

Actual testing and engineering evaluation of the containers include the water spray test, free drop test, compression test, penetration test, and vibration test, reference 49 CFR 173.465. For all gauge models listed above, the radiation survey conducted after each test showed no significant increase in exposure levels. The leak test performed on the source capsule at the conclusion of all tests showed no removable activity. Troxler Electronic Laboratories maintains a complete testing and evaluation report at the corporate office. A copy of this Certification must remain on file as required.